<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <script>
        //判断闰年
        function isRunYear(year) {
            //如果是闰年返回true,否则返回false
            var flag =false;
            if(year%400==0||year%4==0 && year%100!=0){
                flag=true;
            }
           return flag; 
        }
        console.log(isRunYear(2000));
        console.log(isRunYear(1999));
    </script>
</head>
<body>
    
</body>
</html>